1. Technical Field
The present invention relates to an access point for a wireless LAN and a medium access control method thereof. More particularly, the present invention relates to an access point capable of full-duplex communication, and a medium access control method thereof.
2. Description of the Related Art
In the current wireless local area network (WLAN) environment, although a wireless terminal and an access point (AP) may communicate bi-directionally, they transmit and receive data using a half-duplex communication method through which data can be transmitted or received only in one direction at a time. That is, the access point may transmit data to the wireless terminal or another wireless terminal may transmit data to the access point only after data transmission from the wireless terminal to the access point is completed.
In this way, in an existing wireless LAN system using a single antenna, transmission and reception cannot be performed simultaneously, and it is only possible to divide time into very short time units and perform transmission or reception at an allotted time. This is the reason why, while a signal is transmitted using a single antenna, a signal cannot be received through the same antenna. Since a signal transmitted through a wireless medium cannot be received while transmitting due to such a constraint, there is a limit in to wireless LAN performance.
However, as signal processing techniques and antenna techniques have recently advanced, a self-interference cancellation technique which allows simultaneous transmission and reception of data through two or more antennas has recently been developed. A full-duplex communication scheme using a plurality of antennas is a new technique using only one channel, unlike existing methods using a plurality of channels, and, although it is expected to improve performance if the full-duplex communication scheme using a plurality of antennas is adopted in a wireless LAN environment since it can simultaneously transmit and receive data, it is difficult to combine an existing medium access control (MAC) method with conventional full-duplex communication schemes.